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@uitrit tartinel stritt Hirn Letters Patent No. 82,697, dated October 6,1868.

IMPROVEMENT 1N SCREW-Pures.

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TO ALL WHOM IT MAY CONCERN:

Be it known that I, JOHN S. DUTTON, of Ja'rey, in the county ofCheshire, and State'of New Hampshire, have invented a-new and usefulImprovement in Screw-Plates; and I do hereby declare that the followingis a full, clear, and exact description thereof, which will enableothers skilled in the art to make and use the same, reference being hadto the accompanying drawings, forming part ofthis specification.

The drawing represents a screw-plate provided with my invention.

The object of this invention is to provide a convenient means ofcutting'any number of screws of equal size with the ordinaryscrew-plate. n

This I accomplish by means of a gauge-collar, which is movable on thescrew, which closes the dies, and which is further provided with aset-screw to ax it at any point on the said screw, and thus limit themove-- ment of the screw in closing ,the dies. Suitable marks or indicesare-engraved on the collar and on the proxi-r mate reduced end of thescrew-plate, against which the collar is in contactwhen the closing ofthe dies is stopped.

In the accompanying drawing- Ais'an ordinary screw-plate, with dies B Bofthe usual form.

C is the screw for closing such dies upon the Work embraced .by them,and

D is' the handle of the said screw, which serves with opposite similarhandle, forming part of the plate, to operate the tool.

The collar a slips freely on the screw C, and may be held tightly at anypoint by means of the set-screw g or other equivalent device.

The collar is markedv with an index-mark, e, as is' also the reducedcircular end b of the plate A, against which the collar fits withfinished contact when actuated against it.4

The manner ofusing my invention is as follows:

A screw is first cut of the size desired, or.a straight tap is selectedof the desiredsize, either of which is placed in the dies, which arethen closed upon it. The gauge-collar a is then moved down in contactwith the c nd Inland the indices e d brought to coincide. The set-,screwy is then tightened to hold the collar firmly.'

The work is then put in, 1and the screw-plate used in the usual manner.

The shoulderfforming part of the handle D, is graduated with marksperpendicularto the plane of the face ofthe shoulder, which are arrangedto bear a certainv known relation to the'pitch of the screw, whereby onecomplete revolution 'ofthe screw will close the dies a certainpredetermined distance, and-from this device a means of ascertaining thesizeof the screw being cut is obtained, for by looking across from theindex-mark on the collar to the graduations on thc shoulder, the markisnoted, and fraction of a complete turn of the handle is known.

The collar may be placed on a closing-screw when the same is separateand distinct from the handle, as is frequently tho casein screw-plates.

I claim as new, andA desire to secure by Letters Patent- In combinationwithva screw-die plate and theV screw-handle C, the indexed collar ayandthe indexed shoulders t andf, arranged substantially as described. 'l iThe above specication of my invention signed by me, this day of 1868.

JOHN S. DUT'ION.

Witnesses:

J. M. WALES, S. E. KNIGHT.

